Part of the series Orthodox Church
1 Meaning of Orthodox
2 Typica
3 Organization and leadership
4 Number of adherents
5 beliefs
6 Traditions
7 Services
8 Mysteries
9 History
10 Relations with other christians
11 The church today

Eastern Orthodoxy represents the majority of Eastern Christianity. Like Roman Catholics, the Eastern Orthodox trace their bishops back to the apostles through apostolic succession, venerate saints, especially Mary the Mother of God as the Theotokos, pray for the dead, and continue the ancient Christian practice of monasticism. Some, if not all, of these practices are rejected by the majority of Protestant groups, although they are partly retained in some of the earliest liturgical Protestant movements, such as the original German form of Lutheranism. They are also retained by some within the Anglican tradition as Anglicanism is generally considered to be a via media (middle way) between the Roman Catholic and Protestant traditions. Eastern Orthodoxy does not openly promote statuary, although it is not expressly condemned, instead limiting itself primarily to two-dimensional iconography. The Western theological concepts of original sin, predestination, purgatory, and particular judgment have had far less influence in Eastern Orthodoxy and are generally rejected by traditional Eastern Orthodox theologians.

The Eastern Orthodox understand themselves to be the One Holy Catholic and Apostolic Church; the true Church established by Jesus Christ and placed into the care of the apostles. As almost all other Christian groups are in indirect schism with the Eastern Orthodox Church, mostly as a result of the Great Schism with the Roman Catholic Church at the turn of the second Christian millennium (prior to the additional schisms of the Protestant Reformation), these other groups are viewed as being Christian, but who in varying degrees lack full theological orthodoxy and orthopraxy. As such, all groups outside of the Eastern Orthodox Church are not seen as being members of the Church proper, but rather separated brethren who have failed to retain the fullness of the Christian faith as was given to the apostles by Jesus Christ. These deviations from orthodoxy have traditionally been called heresy, but due to the term's immediately pejorative connotations, some prefer the more technical designation of the term heterodoxy.